Chuck adapter



Oct. 17, 1933. G. s. VARCOE ET AL CHUCK ADAPTER Filed Feb. 2, 1931 2Sheets-Sheet 1 INVENTORJ Garland \5. l arcoe 1:]

BY cFc/wz'n A. Pun-077 mag-0%.

Patented Oct. 17, 1933 meat O I CHUCK ADAPTER Garland S. Varcoe, EastCleveland, and Edwin A. Purdy, South Euclid, Ohio Application February2, 1931. Serial No. 512,929

10 Claims.

This invention, as indicated, relates to adjustable chuck engaging anddriving means for laboratory motors and the like. More particularly itcomprises a device which may be provided upon the shaft of a laboratorymotor or the like which will compensate for Wear taking place on theshaft or spindle, or inside the chuck carrying the grinding, cutting,polishing or other appurtenances to be applied to the motor shaft. Thedevice may be in the form of a modified motor shaft terminal or in theform of an attachment provided at its free end with an expansiblefriction spindle in true alignment with the shaft of the motor uponwhich spindle may be engaged the chucks of the usual grinding, cuttingor polishing devices, particularly those used in dental laboratoryoperations, and the like.

Heretofore it has been the practice to engage grinding, cutting andpolishing devices upon the shaft of a laboratory motor by forcing thesame into frictional engagement with the solid tapered end of the shaftof said motor frequently while said motor was revolving at speed.Through the frequent application and detachment of said chucks carryingsuch operating devices there results the wearing away of'the surface ofthe motor shaft or the interior of the chucks, the wear of said partsbeing at the point of attachment of the same, with the result thatultimately the frictional engagement will be insumcient to drive thegrinding, cutting or polishing device, and it will be necessary toimprovise some means of securing the same to the shaft. Such meansordinarily used to cause this frictional engagement comprises thinsheets of paper, wood or metal, and quite frequently the use of suchexpedients throws the grinding, cutting or polishing device out of truealignment or mounts it eccentrically respect to the shaft, and accuratework is therefore impossible.

The present invention has in View the avoidance of the dimculty aboveexplained through the provision of an expansibl terminal provideddirectly on the motor shaft or on an attachment which may be designatedthe chuck adapter, which may be attached to the end of the motor shaftand secured thereto in axial alignment therewith. The free end of themotor shaft or chuck adapter provides a tapered spindle with which thebuiiing and polishing devices may be frictionally engaged in the usualmanner. lhis spindle, in place of being merely a solid shaft as in thecase of the tapered motor shaft now ordinarily provided, is formed withan expansible construction, so that, as Wear takes place it may beslightly adjusted so as to compensate for such wear. Thus the deviceprolongs the usefulness of a laboratory motor and the chuck elements orgrinding, cutting, polishing or like attachment therefor indefinitely inthat a spindle operating in true alignment with the motor shaftmay atall times be assured and such spindle may be maintained in anypredetermined degreeof adjustment, so that frictional engagementtherewith, by a chuck of the character referred to, Will always besufiicient to drive such appur tenances without lost motion and in trueaxial and radial alignment.

Other features and objects of the invention will appear in the courseofthe following description. To the accomplishment of the "fore going andrelated ends, said invention, then, consists of the means hereinafterfully described and particularly pointed out in the claims; the annexeddrawings and the following description setting forth in detail certainmechanism embodying the invention, such disclosed means constituting,however, but several of various mechanical forms in which the principleof the invention may be used.

In said annexed drawings:

Fig. 1 is a side elevation showing a chuck adaptor embodying theprinciples of the invention; Fig. 2 is a central vertical sectional viewtaken along the line 2-2, shown in Fig. 1, looking in the direction ofthe arrows; Fig. 3 is a transverse sectional view taken along the line33, shown in Fig. 2, looking in the direction of the arrows; Fig. t is atransverse sectional view taken along the line 44 shown in Fig. 2,looking in the di rection of the arrows; Fig. 5 is a perspective view ofthe expansible sleeve forming part of the construction; Fig. 6 is a sideelevation of a motor provided with an expansible device embodying theprinciples of the invention mounted on'the projecting tapered end of themotor shaft and showing a chuck and bufling wheel in dotted lines; Fig.7 is an enlarged sectional view show ing the expansible deviceillustrated in Fig. 6; and Fig. 8 is an enlarged sectional View showingan extension knock-off device applied to an adapter of the typeillustrated in Figs. 1 and 2.

As indicated, the drawings show severalforms of construction. Figs. 1 to5 and Fig. 8 show the device in the form of a chuck adapter adapted tobe attached to a standard solid tapered motor shaft, whereas Figs. 6 and7 illustrate the device in connection with the motor shaft itself whichis provided with an extension terminal.

, outer surface 4. The body portion of the device is provided with alarge central bore 5 extending from one end throughout the greaterportion of its length and of a size to closely fit upon the projectingshaft of a laboratory motor or the like. The set screw 6, engaged in atransverse aperture 7 through said body, is adapted to lock the sameupon the shaft of the laboratory motor. The spindle portion of thedevice is provided with a central aperture 8 which communicates with theenlarged bore in the body portion and an adjusting screw 9 is engaged torotate within said bore through the spindle, said adjusting screwprojecting beyond the end of said spindle so as to engage the bodyportion of the expansible sleeve presently to be described. Theadjusting screw, at its inner end, is provided with an enlarged head 11having a screw slot 12 which may be engaged by a suitable implement toturn said adjusting screw as desired. Immediately below the head portionof said adjusting screw, an annular depression 13 is formed, saiddepression being adapted to be engaged by the end of a pin 14 extendingtransversely through the body portion, which holds said screw againstlongitudinal movement, but permits free rotation thereof.

The projecting end of the adjusting screw, as stated, is screwthreadedly engaged with the head 15 of an expansible sleeve 16. Theexpansible sleeve comprises a member having a solid head portioncentrally threaded to receive the adjusting screw and having rearwardlyprojecting members 17 formed by providing a plurality of slots 18 which,in the instance illustrated, are four in number extending from theenlarged end of the sleeve to a point closely adjacent said headportion. The sleeve, as is more clearly shown in Fig. 2, is engaged withthe tapered spindle by having its tapered interior portion 19 engagedover said spindle with the fixed pin 21 on said spindle engaged with oneof the slots of said sleeve, which prevents rotary, but permitslongitudinal movement of said sleeve. The adjusting screw is formed ofsuch length that it will engage through the end wall of said sleeve, butnot extend appreciably beyond the same when the device is expanded tothe degree necessary to frictionally engage the chuck carrying thegrinding, cutting or polishing devices.

The outer surface 22 of the sleeve thus presents a slightly taperedsurface with which said chucks of the grinding, cutting or polishingdevices may be frictionally engaged. This operation is usually performedwhile the motor shaft is revolving at high speed.

When wear takes place upon the outer surface of the expansible sleeve orinterior of chuck all that is necessary to secure the required degree offriction to hold the operating devices in firm engagement with thesleeve, is to turn the adjusting screw slightly in a direction to drawthe sleeve inwardly until the expansible sleeve is moved against thetapered surface of the spindle and expanded to the slight degreenecessary to provide the desired amount of friction. This operation is,of course, carried out while the adapter is removed from the motorshaft. The adapter is then engaged over the motor shaft and locked infirm position thereon by means of the set screw.

The device thus permits the continuous use of the laboratory motor andchucks designed to operate thereon without giving any attention topreserving the same from undue wear on the contacting parts, inasmuch asany wear which takes place may be readily compensated for through theadjustment of the expansible sleeve, and such adjustment always insuresthe accurate alignment and concentricity of the means carrying thebuffing elements which are frictionally applied to the adapter.

The frictional engagement may be made such that all danger of slippageof the grinding, cut ting, polishing or like device will be eliminatedand work of a higher degree of accuracy may thus be carried out throughthe use of a device of this character than where various expedients areresorted to to attach such devices with a sufiicient degree of frictionafter the ordinary motor shaft or chuck socket has become worn. Byapplying an adapter to a new motor shaft for which the adapter isdesigned to be accurately fitted, true alignment of the spindle with themotor shaft is constantly maintained.

The construction illustrated in Figs. 6 and '7 provides for anadjustment of the projecting tapered shaft of the motor, such as is usedin dental laboratories and the like, and which is frequently designateda dental lathe. In such construction the motor 31 is provided at eachend with a projecting shaft 32, the detail construction of which will bepresently described. Inwardly of the projecting end of the shaft a chuckremover 33 is provided, said chuck remover comprising a threaded sleeve34 engaging over a fixed hub 35 on the motor housing, said hub havingcross threads conforming to the threads of said sleeve. The chuckremover is provided at its lower side with a handle 36 by means of whichthe sleeve may be rotated in a direction to move the same outwardlyso asto abut against the end of the chuck and dislodge the same fromfrictional engagement with the motor shaft.

As more particularly illustrated in Fig. 7, the projecting end of themotor shaft is provided with a tapered portion 37, over which is engageda sleeve 38 substantially the same in construction as that illustratedin Figs. 1, 2 and 4, said sleeve having a solid head portion 39centrally threaded to receive an adjusting screw and having rearwardlyprojecting members 41 formed by provid ing a plurality of slots 42,preferably four in number, extending from the enlarged end of the sleeveto a point closely adjacent said head portion. The sleeve is engagedover the tapered surface of the shaft and is held from rotary movementby means of a pin 43 engaged in one of said slots. In order to providefor longitudinal adjustment of said sleeve, the end of the shaft isprovided with an axial recess 44, within which an adjusting screw 45 isengaged for free rotation.

Said adjusting screw is provided with a head 46 on its inner endprovided with an annular groove 47 immediately beneath the same. A pin48, set in a transverse aperture through said shaft is adapted to engagesaid groove and hold said adjusting screw against longitudinaldisplacement. The outer end of the adjusting screw is provided with aslot 49. By means of a screw driver engaged in the slot 49 the adjustingscrew may be rotated in either direction to provide the required degreeof frictional engagement of such end of the shaft with the chucks of thevarious appurtenances which it may be desired to use upon said motorshaft.

It should be explained that where chucks are used on dental lathes whichhavenon-adjustable shafts which have become worn and upon which sectionsof paper or other wedging expedients have been used, some times suchchucks are worn out of true concentricity with the shaft. In such casesit has been found that when such devices are applied to the shaft of amotor or to the spindle of an adapter equipped with the device aboveexplained a species of reaming action takes place which restores theinterior of said chuck to complementary taper and true concentricity.

In the form of construction shown in Fig. 8 a chuck adapter of the typeillustrated in Figs. 1 and 2 is shown as applied to the tapered shaft 51of a dental lathe. The body portion of the adapter, however, is providedwith a sliding bar 52 which is engaged through the longitudinalchannelway 53 formed through said adapter with the inner end of said barclosely adjacent the inner face of the sleeve 54 of the chuck remover,which may be of construction similar to that illus trated in Fig. 6. Theopposite end of said bar projects beyond the outer face 55 of the bodyportion of said adapter so that it may be moved into contact with theend face 56 of a chuck or tapered socket of an operative device, such asa dental laboratory grinding, cutting or polishing tool, applied to theexpansible spindle 57 of the adapter. The bar 52 is provided with a flatsurface 58 on one side and a set screw 59 is engaged through the side ofthe adapter adjacent the channelway 53 on its inner end projecting intosaid channelway at said cut-away portion of the bar. The set screw 59thus serves as a stop to prevent the bar falling from the adapter whenthe same is removed from the dental lathe. As has already been stated,the bar provides for the regular operation of the chuck remover on astandard dental lathe even though the chuck to be removed is spacedoutwardly from said chuck remover a distance slightly greater than thelength of the body portion of the chuck adapter.

Other modes of applying the principle of our invention may be employedinstead of the one explained, change being made as regards the mechanismherein disclosed, provided the means stated by any of the followingclaims or the equivalent of such stated means be employed.

We therefore particularly point out and distinctly claim as ourinvention:

1. An apparatus of the character described including in combination amotor shaft, and means adapted for frictionally engaging operativetapered sockets of devices while said motor is in continuous operation,provided on the end thereof along the axial line of said shaft, saidmeans having a tapered surface, and means for adjusting the degree ofsaid taper.

2. An apparatus of the character described including in combination amotor shaft, and means adapted for frictionally engaging operativetapered sockets of devices while said motor shaft is in continuousoperation, provided on the end thereof along the axial line of saidshaft, said means having a tapered surface, and means for adjusting thedegree of said taper, said means including a rotatable screwlongitudinally fixed with reference to said shaft and engaging ascrew-threaded portion of said means having a tapered surface.

3. An apparatus of the character described including in combination amotor shaft, and means on the end thereof adapted for frictionallyengaging operative tapered sockets of devices while said motor shaft isin continuous operation, said means comprising a tapered supportingmember, a rotatable screw longitudinally fixed with reference to saidmember, and an expansible member non-rotatably engaged on saidsupporting member and presenting a tapered outer surface, andscrew-threadedly engaged with said screw.

l. An apparatus of the character described having in combination a bodyportion and a spindle projecting therefrom, means for engaging said bodyportion on a motor shaft with said spindle in axial alignment therewith,and frictional means presenting a tapered outer surface held againstrotary displacement adapted for securing operative elements with taperedsockets to said spindle while said spindle is in continuous operation.

5. An apparatus of the character described having in combination a bodyportion and a spindle projecting therefrom, means for engaging said bodyportion on a motor shaft with said spindle in axial alignment therewith,means presenting a tapered outer surface held against rotarydisplacement adapted for securing operative elements with taperedsockets to said spindle while said spindle is in continuous operation,and means for adjusting said last-named means.

6. An apparatus of the character described having in combination a bodyportion and a spindle projecting therefrom, means for engaging said bodyportion on a motor shaft with said spindle in axial alignment therewith,frictional means presenting a tapered outer surface held against rotarydisplacement adapted for securing operative elements with taperedsockets to said spindle while said spindle is in continuous operation,and means for adjusting the degree of such frictional engagement.

'7. An apparatus of the character described comprising a body portionhaving a central bore adapted to engage a motor shaft, means for lookingthe same to said motor shaft, and a spindle projecting from said bodyportion in axial alignment with said motor shaft and providing a taperedouter relatively non-rotatable surface adapted for engagement while saidspindle is in continuous operation with operative devices having taperedsockets.

8. An apparatus of the character described comprising a body portionhaving a central bore adapted to engage a motor shaft, means for lockingthe same to said motor shaft, a spindle projeoting from said bodyportion in axial alignment with said motor shaft and providing a taperedsurface adapted for engagement while said spindle is in continuousoperation with operative devices having tapered sockets, and means foradjusting the angular position of said tapered surface.

9. An apparatus of the character described comprising a body portionhaving a central bore adapted to engage a motor shaft, means for lookingthe same to said motor shaft, a spindle projecting from said bodyportion in axial alignment with said motor shaft and providing a taperedsurface adapted for engagement while said spindle is in continuousoperation with operative devices having tapered sockets, means foradjusting the angular position of said tapered surface, and a barengaged in said body member and projecting therefrom parallel to saidspindle to serve as a knock-off extension.

10. An apparatus of the character described having in combination amember providing an enlarged body portion adjacent one end and a taperedspindle at its opposite end, an enlarged end wall and longitudinallyslotted throughout the greater portion of its length in a directiontoward said end Wall to provide expansible members, the end Wall of saidsleeve being provided with a. screw-threaded aperture for engagementwith said adjusting screw, and means to prevent rotary displacement ofsaid sleeve with reference to said spindle.

GARLAND S. VARCOE.

EDWIN A. PURDY.

eERTtFisATE OF ceRRlssrieN.

Patent No. 1,939,669. Qetoher E2, 1933,

GARLANB s. emcee, ET AL.

it. is hereby certified that error appears in the eririterlseecifieetieh of the above numbered patent requiring cerreetion asfollows: Page 3, lines 53 and 61, eleims 1 and 2, respectively, strikeout the word "eperative" and insert the same alter "of" in lines 54 and62., of said claims; line 74 claim 3, strike out the WOId "operative"and insert the same after ei" in same line and claim; and that the saidLetters Patent should be rear? with these eerrections therein that thesame may eenferm to the record ef ease iii the Patent Office.

Signed and sealed this 3rd day of April, A. D. 1934i.

F. M. lispkins (Seal) Acting Csminissieher of i atentsl

